Nanochannels or nanopores with ultra-thin alternating layer properties (i.e., multi-layers of insulator/metal) are very challenging to be fabricated in the nanoscale range (e.g., less than 10 nanometer (nm) channel diameter). While solutions exist to fabricate vertically aligned nanochannels/nanopores, for instance, using highly focused electron beam (e-beam), such as the e-beams used in ultra-high resolution transmission electron microscopy (TEM) systems, to drill individual nanopores on a very small sample, typical sample sizes being less than 10 millimeters (mm)×10 mm, these devices are not ideal from an application point of view.
Furthermore, the solutions are not compatible with large scale integration, thus preventing the advantage of lowering production costs. For example, biosensors that are able to electrically scan genomes are fabricated by atomic layer deposition (ALD) of metal/insulators, in which holes are drilled to form the nanofluidic channel. The hole drilling process is not compatible with large scale integration, and also the vertical alignment is unfavorable. This makes the fabrication of these biosensors very expensive and is in contrast to the original idea that processing sensors using silicon process technology would bring down the cost per sensor.
Accordingly, improved techniques for fabricating horizontally aligned nanochannels would be desirable.